Signal-receiving system



Jan 6, 1931.

F. A. KOLSTER ET AL- sIGNAL RCEIVING/ SYSTEM Filed Nov. -26,1928

PIE 4 NVENToRs:

Patented Jan. 6,v 1931 unfrei)y .STATES PATENT oFF-ice FREDERICK A. KoLsrER AND GECFFREY G.KR'UEsI, oF FALoAL'ro, CALIFORNIA, As-

sIeNoRs rro FEDERAL TELEGRAFF: COMPANY, oFHsAN FRANCISCO, CALIFORNIA, A y

I' SIGNAL-RECEIVING SYSTEM' Application'filed November 26, 1928. 'Serial No..321,831.v

-. This invention relates generally tov systeins for receiving signal energy of radio or carrier frequency. v ,l

It is a general object'of thisinvention to devise a novel resonant' network fortransferring signals of radio or carrier frequency from a source vto detecting lor integrating means. f A

. It is av further object of this invention to devise a novel forrnof network'to be used in a signalqreceivingsystem forthe purpose of amplifyingradio energy. Y l

' It is a further object of this'g-invention to device a novel amplifying networkvof .the

regenerative type which is comparatively:

stable in operation and which is Vparticularly useful in receiving signalenergy of relatively high frequency and short-wavelengths. i. .y l

' The outputicircuitfor relay 13 is desig- `.nated generally at 23,and consistsofindu' :ta-nce 24 shunted 'byvaiiable capacitance 26.

Referring to the vdrawing i j 9:'. "i f Figure y1 is a circuit diagram illustrating one form of our invention.l

i' ao Fig. 2 isa circuitdiagram illustratingthe nature of the network vincorporated inthe system ofFig. 1. Y

Fig. 3 illustrates our inventionas applied to an antenna cooperatively positioned with 'inductance 24 is connected to grid 15 thru .a-blockingycondenser 27 For applying an respect to wave reflecting means.

Y Fig. 4 is a circuit digram.illustrating a radio system incorporating. cascade amplify- A p have :shown-conventional means suc-h as a ing means. c

In radio or carrier, wave receiving systems utilizing electronrelays, it has become con-P ventional kpractice to provide 'reactive input -and output circuitsfor the relays which arej tuned to the .frequency of vsignal energy `to 2 vbe received. This invention differs from conventional systemsyin that input and output circuits provided for one or more ofthe relays are not tuned-tothe'frequency of op` eration, but are interrelated in such a manner as-to form a network resonant as a whole to( the frequencyof operation.

Referring tothe circui .diagram of, Fig.

1, the system therein disclosed utilizes` av source of signal energy of radio or carrier frequency represented by radio antennalO. [For integrating'the signal energy there ,is shown a detector 11of the electron relay type, and

amplifyin yand the antenna there is a'network desig-k nated generally at 12.

-glf'lhe network 12 in its preferred form utilines an electron` relay-13 of conventional Construction, consisting for example of a cathode` 14,7grid 15 and anode 16, positioned within van evacuated envelope.'y The input circuit for this relayihasbeen indicated generallyat nected to the grid and cathode of relay 13.

For example we have shown a direct Conductive connection between grid 15 and one terminal jof inductance 19, `while'the other terininal ofinductance 19 is connected 13o-'cathode ,14- thruy Ya-high frequency by-pass condenser ductance 24C has a direct conductive connec-`v tion to anode 16,while the` other terminal ofV operative anodepotential to the relay-we Bfbattery28, having-its negative terminal iconnected'tocathode14 and its positive terminal connected to vanode 16 thru al suitable Ahigh frequency choke 29. rlhe cathode of relay 13 is also shown as heated by a source of current conventionally represented by A battery 31.`

4In practice .theinput circuitf18 is suitably coupled to a source of signal energy, such as antenna 10,-'while output circuit 23 is coupled to the input circuit of further radiovr frequency means or to the input of detector relay 11. orconvenience relay k11 has. been shown asbeing of the conventional type having an input circuit 32 inductively coupled to circuit 23 of amplifying relay 13. lThe audio frequency` output of relay 11 can be reinforced by repeating the same thru audio frequency amplifierr 33 and is then impressed s H50 interposed betWeenthe inputef thisfdetectorilupon asuitab1e translator 34, A

Inthat form of the invention shown in Fig. l We have incorporated means for mod? its grid connected to a suitable source of audio Y pleted thru the the network is operating regeneratively, it is relatively stable'and will not readily spill,y

frequency current indicated by oscillator 37. The anode and cathode of this relay are connected acrossan inductance 38, which in turn ,is included in the gridrathode circuit 18. l As the potential upon the grid of relay'36 is varied the plate-cathode impedance is likewise varied so as to vary the translating char,- V acteristics of network 12. Since the network12 is generally operated regeneratively, we preferably provide means `wherebythe'degree of regeneration'can be controlled. Such means can be formedby a resistance 39 connected across A'battery31. This resistance' has a variableY tap 41 `connected to the return lead for input circuit 18. The operationrof networkA 12 can bestY be explained by reference tothe simplified diagram of Fig. 2. It will be noted that thereactive input and output circuits 18 and-23 5 respectivelyrare intercoupled thru the anodecathode capacitance of relay 13 indicated at 42. Assuming now that. input fcircuit 1:8 is

lnegatively reactive and/output circuit` 23 positively reactive with respect to a desired 0 frequency of operation, these circuits when takenin conjunction withi--the inter-coupling capacitance 42 form an electrical Vnetworkl which is resonant to a givenfrequency of A operation. For example in a given' instance 5`input circuit18 was adjustedso as to be Y individually resonant to afrequency 05.216,20()

kilocycles and output circuit 23 adjusted so 'asrto be individually resonant to afrequency of 18,500 kilocycles,'in order to make the net- 17,900 kilocycles.

will vary somewhat forl relays of different construction and'for circuits having different inductance to capacitance ratios. Generally the inductance of circuit 23 is made relatively l nents, andl in fact the capacitance 26 can be r-educed to zero.` In this event circuit 23`is coingrid anode capacitance; of A relay '13.' Y

Y The network as described above lisavone- `way device and will therefore amplify current variations impressed upon its input.

systemof Fig. 1 the degree of regeneration Y can be controlled kby varying the position of tapk 41. It has been found that even when over kinto local oscillation.

95 ln'Fig. 3 we have Yshown ra radio system work as a whole resonant to a frequency of 'V It is'apparent-that the individual adjustment of circuits 18 and 23. relay.

Furthermore with properadjustment of theY ,21, 1928. Aslexplained in said copending application,"the Wave length of operation mustbeara definite relationship to the' focal length ofthe reector, as for example the Wave length can be four times the focal wave length;` Thevelfective length of the antenna conductor should also be about one half the VWave length of'energyto be received. The lresonant network 12 f'in Ythis caselias been means has beenY o1nitted.-` i Fig. 4`We have shown a system utilizing our' invention :in which two resonant netmodiiied to the extent thattthemodulating VWorks12a and 12b are connected vin cascade andare interposed between the sourceof Y signal energy andthe integratingy means. In

this case the respective input and output circuits for' the networks are tuned in such a manner that ,each network is resonant to the samefrequency of operation.

l 1.A. signal receiving systemcomprising a;

source of signal energy of radio frequency, an V.elec-tron relay having grid, cathode and anode electrodes, a reactive input circuitconnected across the grid and ycathode Ofsaid relay'i'and coupled to said source, vand a reactive output circuitv connected across the `grida-nd anode' of said relay, said circuits eing oppositely reactive with respect to a given frequency of operation and affording a network resonant as a whole to said fre.;

quency ofv operation inconjunction with said Y, 2. A signalreceiving system comprising a source of signal energy of radio frequency, an electron relay having grid, cathode and anode electrodes, a'reactive'input circuit connected Vacross the grid and cathode of said relay and coupled" to said" source, and areactive outputcircuit connected across the grid and anode of -said relay, said input circuit being non-resonant of itselfto Athe frequency of operation but said 'circuits-taken together and in conjunctionwith the capacitance' between the cathode and anode forming a network resonantv asa whole to said frequency of Y operation.

Y 3.A The method of receiving signal energy of radio frequency characterized by the use of an'electron relay having reactive input and-.output circuits connected to the same,

said method comprising adjust-ing said circuits so that they Vare individually non-resonant to the frequency of said signalV energy ``and interrelating said circuits thi-'u1 said re-V lay whereby a network is formed which is y nant to the frequency of said signal energy and intercoupling said circuits thru the 'anode-cathode capacitance of the relay whereby a network is formed which is resonant to said frequency.

In testimony whereof, we have hereunto set our hands.

FREDERICK A. KOLSTER. yGEOFFREY G. KRUESI. 

